Control valves are known that use a solenoid actuator to switch open or closed the interface between a spool valve and a valve body. U.S. Pat. No. 8,333,362 discloses one such valve. In order to account for pressure acting on the valve body, this reference attaches a separate pressure balancing component to the armature and valve insert that can be acted on by opposing forces of the pressure medium so that the forces cancel each other out and reduce the force needed to open the actuator.
One type of control valve is an electrohydraulic switching solenoid valves that is used to control engine valve train systems as well as in other applications. The response time of the solenoid is an important part of the overall valve train system timing and performance. It is desirable to minimize system response time and variation in that time so that engine performance and/or fuel consumption are optimized at various operating conditions.
In most conventional solenoid valve designs, the internal force balance is affected by hydraulic force due to the supply pressure acting on one or more of the exposed cross-sectional areas. Normal variation in the supply pressure creates unwanted variation in the solenoid on and off response times.
It would be desirable to reduce response time variation due to changes in supply pressure and improve the accuracy of on and off response times. It would also be desirable to maintain the same overall size of the valve assembly for drop-in replacement of existing valves. Further, it would be desirable to achieve this at the same or reduced cost without complicating the assembly process for the known valves.